This invention relates to a new composition utilizable for both hair waving and setting. More particularly, this invention relates to a hair-waving composition comprising one or more of specific wave accelerating agents selected from alkylene carbonates, alkyl carbamates and .gamma.- or .delta.-lactones in addition to the main sulfite or bisulfite waving agent. By the use of this composition, strong permanent waves can be created in hair with greater safety within the pH range of human skin at a low temperature without any unpleasant odor.
The formation of waves in hair is achieved by a combination of the steps of subjecting the hair to a reducing treatment for reductively disrupted cystine linkages (--S--S--) in hair keratin, artificially curling the reductively treated hair by the aid of a rod or the like to form waves and oxidizing the treated hair naturally or by the aid of an oxidizing agent to regenerate cystine linkages in the hair for setting the waves.
Chemicals utilizable in the formation of waves in hair are generally called waving agents and various compounds have been proposed hitherto as such agents. Most widely used at present among such waving agents is the so-called "cold wave solution". According to the conventional method utilized for the cold wave lotion, hair is reductively treated with a waving solution containing as the main waving agent a mercapto compound such as a thioglycolate and then with a neutralizing solution containing a bromate, perborate, or hydrogen peroxide to effect oxidation. This method enables the formation of satisfactory permanent waves at room temperature but still retains many problems to be solved from the standpoint of environmental hygiene and safety in the course of operation. The aforesaid waving solution emits a strong unpleasant odor due to a mercapto compound used therein and bothers operators and customers alike with an unpleasant feeling. This waving solution has to be combined with an alkaline substance such as ammonia as waving accelerating agent. However, addition of an alkaline substance such as ammonia not only brings about an increase in the unpleasant odor but also induces a significant increase in the pH of the solution, thus causing irritation when the solution is brought into contact with the skin.
In the past, hair waving methods wherein a sulfite or bisulfite is used as waving agent were proposed. For example, U.S. Pat. No. 2,400,377 discloses a waving agent which comprises a mixture of an alcohol and water having a bisulfite dissolved therein and British Pat. No. 591,932 discloses a treating agent which comprises a mixture of an alcohol and water having a sulfite dissolved therein. These waving agents were insufficient to produce a satisfactory strong wave in the hair. Accordingly, there is a great demand for a hair-waving product which is satisfactory in hair-waving effect and harmless in handling and hygiene without any unpleasant odor.